Input of terrestrial insects was sampled temporally and diurnally in Waterloo Creek near Dorchester, Iowa. Sampling consisted of six, four-hour time periods over a 24-hour cycle during June, July and August of 2004. Clearing nets were used to remove all inputs from upstream. Collecting nets were placed 10 m downstream from the clearing nets to capture all terrestrial insects falling onto the water surface between the clearing nets and collecting nets. Aquatic and terrestrial insects were separated, then identified to order, family and morpho-species. Species richness, abundance, and biomass were quantified. Generally, more terrestrial insects occurred during the daytime hours. Seasonal variation will also be presented.